Arthritis In Rats Research Articles

In vitro and in vivo modulatory effects of fluoxetine on gene expression and antioxidant enzymes in CFA-induced chronic inflammatory model: drug repurposing for arthritis.

Fluoxetine, being a selective serotonin uptake inhibitor, has been broadly used to modulate the neurotransmission of serotonin in the central nervous system. Fluoxetine performs a number of crucial central nervous system-related tasks, including neuroprotective effects against microglial neurotoxicity and protecting oxidative cell damage produced by stress in a variety of stress-related unfavourable health disorders. Studies have shown that the drug (fluoxetine) also has analgesic and anti-inflammatory characteristics in addition to its other basic benefits. Furthermore, existing treatment approaches (NSAIDs, DMARDs, corticosteroids and other immunosuppressants) for RA have limited effects on chronic immunological models. These facts served as the basis for carrying out a study on fluoxetine to explore its therapeutics in a chronic inflammatory rat model called Freund's complete adjuvant (FCA)-induced arthritis. The therapeutic effect of the fluoxetine in FCA-induced arthritic rats was assessed by paw volume, paw diameter, arthritic index and body weight at specific days through the experiment of 28days. These findings were further co-investigated by haematological, biochemical parameters and radiographic imaging at the end of experiment. Furthermore, the modulatory effects on gene expression (NF-κB, PGE2, COX2, INF-γ, IL-4 and IL-10) and antioxidant properties were gritty using qRT-PCR and ELISA kits, respectively, in experimental arthritic rats. Fluoxetine at 10, 20 and 40mg/kg doses reduced (p < 0.001) the serum concentration of C-reactive protein and rheumatoid factor as well as suppressed the expression of PGE2, NF-kB, COX2 and INF-γ when compared to arthritic control. Moreover, fluoxetine (at higher doses) caused significant rise of IL-4 and IL-10. These findings supported the anti-inflammatory and antioxidant potential of fluoxetine in chronic inflammatory model and endorsed it for clinical trials.

Evaluation of Anti-arthritic Activity of hydro-alcoholic Root Extract of Moringa concanensis in complete Freund’s Adjuvant-induced Arthritic Rats

Background: Arthritis, a debilitating inflammatory disorder, has been a target for numerous therapeutic interventions. Natural plant extracts, especially those rich in phytochemicals like terpenoids, have demonstrated potential as alternative remedies. In this context, Moringa concanensis, a traditionally known medicinal plant, needs further elucidation regarding its anti-arthritic efficacy. Objective: This study aimed to investigate the anti-arthritic potential of the hydro-alcoholic root extract of Moringa concanensis in a Complete Freund’s Adjuvant (CFA)-induced arthritis rat model. Methods: An initial phytochemical screening and GC-MS analysis were executed on the hydro-alcoholic root extract of Moringa concanensis. Arthritis was subsequently induced in rats using CFA. Comprehensive assessments were made on various parameters such as body weight, paw volume, joint diameter, serum rheumatoid factor, serum C-reactive protein, ALP, ALT, total protein, total cholesterol, and urea. Additionally, histopathological studies of the liver and ankle joints were carried out. For comparative efficacy, methotrexate was employed as a positive control. Results: Rats receiving the hydro-alcoholic extract at dosages of 200mg/kg (p.o) and 400mg/kg (p.o) exhibited a notable reduction in the physical and biochemical indicators of arthritis, in comparison to the untreated arthritic model. Histopathological observations further confirmed that the anti-arthritic effects of the hydro-alcoholic extract were on par with methotrexate. Conclusion: The hydro-alcoholic root extract of Moringa concanensis exhibited significant anti-arthritic activity, possibly attributed to its terpenoid content. The findings advocate for its potential application as a therapeutic agent in managing arthritis.

Uncovering the mechanisms of Zhubi decoction against rheumatoid arthritis through an integrated study of network pharmacology, metabolomics, and intestinal flora

Ethnopharmacological relevanceZhubi Decoction (ZBD) is a modified formulation derived from the classic traditional Chinese medicine prescription “Er-Xian Decoction” documented in the esteemed “Clinical Manual of Chinese Medical Prescription”. While the utilization of ZBD has exhibited promising clinical outcomes in treating rheumatoid arthritis (RA), the precise bioactive chemical constituents and the underlying mechanisms involved in its therapeutic efficacy remain to be comprehensively determined. Aim of the studyThis study aims to systematically examine ZBD's pharmacological effects and molecular mechanisms for RA alleviation. Materials and methodsUtilizing the collagen-induced arthritis (CIA) rat model, we comprehensively evaluated the anti-rheumatoid arthritis effects of ZBD in vivo through various indices, such as paw edema, arthritis index, ankle diameter, inflammatory cytokine levels, pathological conditions, and micro-CT analysis. The UPLC-MS/MS technique was utilized to analyze the compounds of ZBD. The potential therapeutic targets and signaling pathways of ZBD in the management of RA were predicted using network pharmacology. To analyze comprehensive metabolic profiles and identify underlying metabolic pathways, we conducted a serum-based widely targeted metabolomics analysis utilizing LC-MS technology. Key targets and predicted pathways were further validated using immunofluorescent staining, which integrated findings from serum metabolomics and network pharmacology analysis. Additionally, we analyzed the gut microbiota composition in rats employing 16 S rDNA sequencing and investigated the effects of ZBD on the microbiota of CIA rats through bioinformatics and statistical methods. ResultsZBD exhibited remarkable efficacy in alleviating RA symptoms in CIA rats without notable side effects. This included reduced paw redness and swelling, minimized joint damage, improved the histopathology of cartilage and synovium, mitigated the inflammatory state, and lowered serum concentrations of cytokines TNF-α, IL-1β and IL-6. Notably, the effectiveness of ZBD was comparable to MTX. Network pharmacology analysis revealed inflammation and immunity-related signaling pathways, such as PI3K/AKT, MAPK, IL-17, and TNF signaling pathways, as vital mediators in the effectual mechanisms of ZBD. Immunofluorescence analysis validated ZBD's ability to inhibit PI3K/AKT pathway proteins. Serum metabolomics studies revealed that ZBD modulates 170 differential metabolites, partially restored disrupted metabolic profiles in CIA rats. With a notable impact on amino acids and their metabolites, and lipids and lipid-like molecules. Integrated analysis of metabolomics and network pharmacology identified 6 pivotal metabolite pathways and 3 crucial targets: PTGS2, GSTP1, and ALDH2. Additionally, 16 S rDNA sequencing illuminated that ZBD mitigated gut microbiota dysbiosis in the CIA group, highlighting key genera such as Ligilactobacillus, Prevotella_9, unclassified_Bacilli, and unclassified_rumen_bacterium_JW32. Correlation analysis disclosed a significant link between 47 distinct metabolites and specific bacterial species. ConclusionZBD is a safe and efficacious TCM formulation, demonstrates efficacy in treating RA through its multi-component, multi-target, and multi-pathway mechanisms. The regulation of inflammation and immunity-related signaling pathways constitutes a crucial mechanism of ZBD's efficacy. Furthermore, ZBD modulates host metabolism and intestinal flora. The integrated analysis presents experimental evidence of ZBD for the management of RA.

Diospyros kaki fruit extract produces antiarthritic and antinociceptive effects in rats with complete Freund's adjuvant-induced arthritis.

Current treatments for rheumatoid arthritis produce untoward effects; thus, considerable effort has been made to recognize effective herbal medicines against the condition. In the present study, the therapeutic effect of Diospyros kaki fruit hydroalcoholic extract (DFHE) on complete Freund's adjuvant (CFA)-induced arthritis in rats was investigated. The extract was characterized using liquid chromatography-electrospray mass spectrometry (LC-ESIMS). Male Wistar rats were grouped as follows (eight rats in each): control, CFA, CFA + indomethacin (5 mg/kg), CFA + DFHE (50 mg/kg), and CFA + DFHE (100 mg/kg). Paw volume, mechanical allodynia, thermal hyperalgesia, and arthritis score were evaluated. Serum levels of malondialdehyde (MDA), thiol groups, tumor necrosis factor-alpha (TNF-α), as well as glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were evaluated. Carotenoids were found to be the major components of DFHE. Administration of DFHE (100 mg/kg) significantly decreased arthritis score, paw volume, and thermal hyperalgesia, and improved mechanical allodynia. MDA and TNF-α levels were decreased while thiol levels and SOD and GPx activities were increased in DFHE-treated groups compared to the CFA group. These results suggest that D. kaki extract caused an improvement in clinical signs of rheumatoid arthritis symptoms possibly through suppression of oxidative stress and inflammation.

Discovery of CYP2E1 as a novel target in rheumatoid arthritis and validation by a new specific CYP2E1 inhibitor

Considerable evidence indicates that CYP2E1 is associated with a variety of inflammatory diseases. Here we evaluated CYP2E1 as a potential therapeutic target for rheumatoid arthritis (RA) and established the protective effect of a new CYP2E1 inhibitor. Gene-expression datasets were used to analyze the change in expression of CYP2E1 in RA patients; CYP2E1 activity in collagen-induced arthritis (CIA) rats was determined by HPLC. We further evaluated the protective effects of Cyp2e1 knockout and a CYP2E1-specific inhibitor, Q11, synthesized by our group, in CIA and adjuvant-induced arthritis (AIA) rats. The expression of CYP2E1 in synovial tissue was elevated in RA patients and in CIA rats and the activity of CYP2E1 in vivo and in vitro in CIA rats was greater than that of controls. Cyp2e1 knockout significantly reduced the incidence of CIA and alleviated the severity of symptoms. Treatment with different doses of Q11 decreased paw thickness, volume and arthritis scores and reduced the serum levels of IL‐6, TNF‐α, IL‐1β and MDA, and increased the level of GSH in CIA rats. A similar inhibitory effect was exhibited for Q11 in the AIA rats. Moreover, Q11 significantly impeded proliferation, migration, and invasion of human rheumatoid arthritis synovial fibroblasts cells. Q11 decreased the release of ROS and enhanced Nrf2 nuclear translocation and HO-1 expression in the cell nucleus. Overall, our results indicated that CYP2E1 may be a new target for RA and Q11 has potential protective effects against RA by reducing oxidative stress and opposing the inflammatory response via the ROS/Nrf2/HO-1 signaling pathway.

Rational formulation of saponin and dexamethasone for the synergistic treatment of rheumatoid arthritis in vivo

Rheumatoid arthritis (RA) is a common autoimmune disease, and the abnormal proliferation of fibroblast-like synoviocytes (FLSs) in inflamed joints plays a key role in the pathogenesis of RA, which has become an important therapeutic target for RA treatment. This work reported a facilely formulated nanoparticle from saponin (Sap) and dexamethasone (Dex) in precise ratio, affording the resultant Dex@Sap nanoparticles. Benefiting from the enlargement of vascular endothelial cell gap at the inflammation site and intra-articular injection, Dex@Sap could accumulate at the inflamed joints to inhibit excessive proliferation of FLSs and mediate cell apoptosis, achieving symptomatic relief and efficient RA treatment, while reducing the amount of drug needed as well as the occurrence of adverse reactions. Typical AKT (also known as protein kinase B, PKB)/mTOR (mammalian target of rapamycin) pathway was observed to be inhibited, and the mitochondria-mediated intracellular reactive oxygen species (ROS) level was also upregulated by Dex@Sap. Further in vivo evaluations demonstrated that Dex@Sap could significantly alleviate RA-induced inflammatory response and the expression of pro-inflammatory cytokines to cure joint damage in collagen-induced arthritis mice and rats. This work provides a clinically promising nanomedicine to synergistically treat RA.

Sinapic acid-pullulan based inflammation responsive nanomicelles for the local treatment of experimental inflammatory arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disorder of joints. It is one of the major causes of disability and morbidity worldwide. Administration of conventional drugs through the systemic route restricts the bioavailability of drugs, systemic toxicity, and reduced efficacy. We have introduced Rebamipide (Reb)-loaded Sinapic acid (SA)-Pullulan (PL) nanomicelles (Reb@SA-PL NMs), a nanotechnology based drug delivery system for the treatment of inflammatory arthritis. PL is a polysaccharide obtained from the fungus Aureobasidium pullulans, and SA is a bioactive polyphenol found in various plants. Both are classified by US-FDA Generally Recognised as Safe (GRAS) materials. Reb@SA-PL NMs found to be cytocompatible. Subsequently, intra-articular administration of Reb@SA-PL NMs enhances the anti-arthritic potential compared to free Reb drug in collagen-induced experimental inflammatory arthritis rat model. Reb@SA-PL NMs reduced the expression of RANKL receptor and Nf-κB. Reb@SA-PL NMs reverses the breakdown of type II collagen, MMP-13, and inhibits the pro-inflammatory markers. Reb@SA-PL NMs prevented bone erosion, cartilage degradation, joint oedema, and synovial inflammation. The results of the study demonstrated that Reb@SA-PL NMs, an enzyme-responsive drug delivery system, has excellent potential for alleviating inflammatory arthritis by blocking MMP-13 and RANKL.

Ethanolic Extract of Equisetum arvense: A Potential Agent against Rheumatoid Arthritis in Wistar Rats with Freund’s Complete Adjuvant-Induced Arthritis

Ethanolic Extract of Equisetum arvense: A Potential Agent against Rheumatoid Arthritis in Wistar Rats with Freund’s Complete Adjuvant-Induced Arthritis

Targeting next-generation PDE4 inhibitors in search of potential management of rheumatoid arthritis and psoriasis

Immune-mediated inflammatory diseases (IMIDs) comprise a broad spectrum of conditions characterized by systemic inflammation affecting various organs and tissues, for which there is no known cure. The isoform-specific inhibition of phosphodiesterase-4B (PDE4B) over PDE4D constitutes an effective therapeutic strategy for the treatment of IMIDs that minimizes the adverse effects associated with non-selective PDE4 inhibitors. Thus, we report a new class of isoquinolone derivatives as next-generation PDE4 inhibitors for effective management of rheumatoid arthritis (RA) and psoriasis. Among the series, 8 compounds i.e. 1e, 1l, 1m, 1n, 1o, 2m, 2o and 3o showed promising PDE4B inhibition (>80 %) in vitro with IC50 ∼ 1.4–6.2 µM. The compound 1l was identified as an initial hit and was pursued for further studies. According to structure–activity relationship (SAR), an allyl group at C-4 position improved PDE4B inhibition. The correlation between in vitro activity data and binding affinities obtained via molecular docking suggested that the high-affinity binding to PDE4B is a prerequisite for the effective inhibition of PDE4B. Notably, the hit 1l showed selectivity towards PDE4B over PDE4D in vitro. Furthermore, 1l treatment (30 mg/kg) in the adjuvant-induced arthritis (AIA) rat model induced by complete Freund’s adjuvant (CFA) demonstrated anti-arthritic potential via ameliorating paw swelling and body weight, narrowing joint space, reducing excessive immune cells infiltration and pannus formation in addition to reducing mRNA expression of pro-inflammatory cytokines such as TNF-α and IL-6 in synovial tissues of experimental rats. Additionally, 1l reduced the hyper-proliferative state and colony forming potential of IMQ-induced psoriatic keratinocytes. The treatment of these cells with 1l markedly reduced the protein levels of Ki67 and mRNA levels of pro-inflammatory cytokines e.g. IL-17A and TNF-α suggesting its potent anti-psoriatic potential. Furthermore, 1l did not show any significant adverse effects when evaluated in a systematic toxicity (e.g. teratogenicity, hepatotoxicity and cardiotoxicity) studies in zebrafish at the tested concentrations (1–100 µM) and the NOAEL (no-observed-adverse-effect level) was found to be 100 µM. Thus, with promising anti-inflammatory effects both in vitro and in vivo along with PDE4B selectivity with an acceptable safety margin, 1l emerged as a new and promising inhibitor for further studies.

The Combined Effect of Curcumin and Crocin on the Reduction of Inflammatory Responses in Arthritic Rats.

The present study evaluated the anti-arthritic impact of combined crocin and curcumin on Adjuvant Induced Arthritis (AIA) in rats. The arthritis model was induced in rats by injecting Complete Freund's adjuvant (CFA) into the right hind paw and was subsequently treated with crocin and curcumin. Evaluation of anti- arthritic activity was carried out using paw swelling, hematological parameters, biochemical parameters, inflammatory cytokines, and histopathology of rats. The results showed increased paw swelling, increased serum markers levels, including CRP, RF, ALP, ALT, and AST, and inflammatory cytokines (ILlβ and TNFα) along with histology changes (cartilage and bone degradation) in arthritic rats when compared to the normal group. Crocin, curcumin and crocin + curcumin administration at different doses (especially combination at 40 mg/kg and 30 mg/kg, respectively), as well as MTX, revealed a suitable therapeutic effect on AIA rats. Moreover, both phytochemicals and their combination at different doses showed effective anti- arthritic effects owing to their anti-inflammatory effects. Crocin and curcumin, either alone or in combination, can be a suitable treatment modality for rheumatoid arthritis.

Study on the anti-inflammatory mechanism of moxibustion in rheumatoid arthritis in rats based on phospholipaseA2 signaling inhibition by Annexin 1.

To determine whether moxibustion had an anti-inflammatory effect on rheumatoid arthritis (RA) by regulating Annexin 1 expression and interfering with the phospholipaseA2 signaling pathway. Thirty male Sprague-Dawley rats were randomly categorized into five groups (six rats per group): blank control (CON) group, RA model (RA) group, moxibustion (MOX) group, Annexin 1 lentiviral intervention (RNAi-Anxa1) group, and Annexin 1 lentiviral intervention + moxibustion (RNAi-Anxa1 + MOX) group. The rats in the RNAi-Anxa1 and the RNAi-Anxa1 + MOX groups were injected with the lentiviral vector-mediated RNAi-Anxa1 into the rat foot pad. An experimental RA rat model was established by injecting Freund's complete adjuvant (FCA) into the RA, MOX, RNAi-Anxa1, and RNAi-Anxa1 + MOX groups. Rats in the MOX and RNAi-Anxa1 + MOX groups received moxibustion treatment. After modeling, using moxibustion "Shenshu (BL23)" and "Zusanli (ST36)", each point is 5 times, bilateral alternating, once a day, 6 times for a course of treatment, between the courses of rest for a one day. A total of three treatment courses were conducted. Both bilateral pad thicknesses were measured using Vernier calipers on experimental days 1, 7, 14, 21, and 28. The expression of cPLA2α signaling in the synovium of diseased joints was observed using Western blot. The pathology of the rat ankle synovium was observed using hematoxylin-eosin (HE) staining. Interleukin (IL)-1β, IL-10, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) were detected using enzyme-linked immunosorbent assay. Moxibustion increased the levels of Annexin 1 and decreased the inflammatory response in rats with RA. After increasing the expression of Annexin 1, the phosphorylated expression of cPLA2α was inhibited, the serum levels of IL-1β, PGE2, and LTB4 decreased, and the level of IL-10 increased. In moxibustion treated RA rats after the Annexin 1 lentiviral intervention, the serum levels of IL-1β, PGE2, LTB4, and IL-10 were almost unchanged. Moxibustion enhanced the negative regulation of the cPLA2α signaling pathway, increased the synovial Annexin 1 expression, inhibited the cPLA2α signaling pathway, indirectly inhibited the expression of downstream inflammatory factors, and played a role in reducing inflammation.

Anti-inflammatory Properties of Tongfeng Li'an Granules in an Acute Gouty Arthritis Rat Model.

To examine the anti-inflammatory properties and underlying mechanisms of Tongfeng Li'an Granules (TFLA), a traditional medicine, in acute gouty arthritis using a rat model. We identified 55 major compounds in TFLA via ultrahigh-performance liquid chromatography connected to quadrupole time-of-flight mass spectrometry (UPLC-TQF-MS/MS). Databases were employed for the prediction of potential targets, followed by PPI network construction as well as GO and KEGG analyses. After network-pharmacology-based analysis, a rat gouty arthritis model was used to validate the anti-inflammatory mechanism of TFLA. UPLC-TQF-MS/MS and network pharmacology analyses revealed 55 active ingredients and 160 targets of TFLA associated with gouty arthritis, forming an ingredient-target-disease network. The PPI network identified 20 core targets, including TLR2, TLR4, IL6, NFκB, etc. Functional enrichment analyses highlighted the Toll-like receptor signaling pathway as significantly enriched by multiple targets, validated in in vivo experiments. Animal experiments demonstrated that TFLA improved pathological changes in gouty joint synovium, with decreased ankle joint circumference, serum IL6, IL10, and TNFα levels, as well as reduced protein and mRNA expression of NLRP3, TLR2, and TLR4 in ankle joint synovial tissue observed in the middle- and high-dose TFLA and positive control groups compared to the model group (p < 0.05). This research elucidated the pharmacological mechanisms of TFLA against gouty arthritis, implicating various ingredients, targets, and signaling pathways. Animal experiments confirmed TFLA's efficacy in alleviating inflammation in acute gouty arthritis by modulating Toll-like receptor signaling and NLRP3 expression.

The anti-rheumatoid arthritic activity of Artemisia ordosica Krasch. (traditional Chinese/Mongolian medicine) extract in collagen-induced arthritis in rats.

Rheumatoid arthritis (RA) seriously affects the daily life of people. The whole plant of Artemisia ordosica Krasch. (AOK) has been used in folk medicine. This study aimed to investigate the in vivo anti-RA effects of AOK extract (AOKE) on collagen-induced arthritisin rats. AOKE (400, 200, or 100mg/kg) was administered orally to animals for 30 days. Body weight, paw swelling, arthritis index, thymus, and spleen indices, and pathological changes were assessed for effects of AOKE on RA. Furthermore, the inflammatory cytokines in rat serum were detected. In addition, the expressions of STAT3, Caspase-3, Galectin-3, and S100A9 in synovial tissue were researched using immunohistochemistry. The AOKE significantly reduced the arthritis indices, paw swelling, spleen, and thymus indices. Meanwhile, AOKE (400mg/kg) decreased the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-17A, and increased the level of IL-10 in rat serum. Histopathological examination showed that AOKE reduced inflammatory cell infiltration and cartilage erosion. Then, AOKE decreased the expressions of STAT3, Galectin-3, S100A9, and increased the expression of Caspase-3. AOKE had interesting anti-RA activity in rats, which deserved further research for the development and clinical use of this medicinal resource.

Fu-zi decoction attenuate rheumatoid arthritis in vivo and in vitro by modulating RANK/RANKL signaling pathway.

Fu-zi decoction (FZD) has a long history of application for treating Rheumatoid arthritis (RA) as a classic formulation. However, its underlying mechanisms have not been fully elucidated. This study aimed to decipher the potential mechanism of FZD in treating RA, with a specific focus on receptor activator of nuclear factor κB/receptor activator of nuclear factor κB ligand (RANK/RANKL) signaling pathway. The impact of FZD on RA was investigated in collagen-induced arthritis rats (CIA), and the underlying mechanism was investigated in an osteoclast differentiation cell model. In vivo, the antiarthritic effect of FZD at various doses (2.3, 4.6, 9.2g/kg/day) was evaluated by arthritis index score, paw volume, toe thickness and histopathological examination of inflamed joints. Additionally, the ankle joint tissues were determined with micro-CT and safranin O fast green staining to evaluate synovial hyperplasia and articular cartilage damage. In vitro, osteoclast differentiation and maturation were evaluated by TRAP staining in RANKL-induced bone marrow mononuclear cells. The levels of pro- and anti-inflammatory cytokines as well as RANKL and OPG were evaluated by ELISA kits. In addition, Western blotting was used to investigate the effect of FZD on RANK/RANKL pathway activation both in vivo and in vitro. FZD significantly diminished the arthritis index score, paw volume, toe thickness and weigh loss in CIA rats, alleviated the pathological joint alterations. Consistent with in vivo results, FZD markedly inhibited RANKL-induced osteoclast differentiation by decreasing osteoclast numbers in a dose-dependent manner. Moreover, FZD decreased the levels of pro-inflammatory cytokines IL-6, IL-1β and TNF-α, while increasing anti-inflammatory cytokine IL-10 level both in serum and culture supernatants. Treatment with FZD significantly reduced serum RANKL levels, increased OPG levels, and decreased the RANKL/OPG ratio. In both in vivo and in vitro settings, FZD downregulated the protein expressions of RANK, RANKL, and c-Fos, while elevating OPG levels, further decreasing the RANKL/OPG ratio. In conclusion, FZD exerts a therapeutic effect in CIA rats by inhibiting RANK/RANKL-mediated osteoclast differentiation, which suggested that FZD is a promising treatment for RA.

Temperature‐Activated Near‐Infrared‐II Fluorescence and SERS Dynamic‐Reversible Probes for Long‐Term Assessment of Osteoarthritis In Vivo

AbstractThe abnormal fluctuation of temperature in vivo usually reflects the progression of inflammatory diseases. Noninvasive, real‐time, and accurate monitoring and imaging of temperature variation in vivo is advantageous for guiding the early diagnosis and treatment of disease, but it remains difficult to achieve. Herein, we developed a temperature‐activated near‐infrared‐II fluorescence (NIR‐II FL) and surface‐enhanced Raman scattering (SERS) nanoprobe for long‐term monitoring of temperature changes in rat arthritis and timely assessment of the status of osteoarthritis. The thermosensitive polymer bearing NIR‐II FL dye was grafted onto the surface of nanoporous core‐satellite gold nanostructures to form the nanoprobe, wherein the nanoprobe contains NIR‐II FL and Raman reference signals that are independent of temperature change. The ratiometric FL1150/FL1550 and S1528/S2226 values of the nanoprobe exhibited a reversible conversion with temperature changes. The nanoprobe accurately distinguishes the temperature variations in the inflamed joint versus the normal joint in vivo by ratiometric FL and SERS imaging, allowing for an accurate diagnosis of inflammation. Meanwhile, it can continuously monitor fluctuations in temperature over an extended period during the onset and treatment of inflammation. The tested temperature change trend could be used as an indicator for early diagnosis of inflammation and real‐time evaluation of therapeutic effects.

Temperature-Activated Near-Infrared-II Fluorescence and SERS Dynamic-Reversible Probes for Long-Term Assessment of Osteoarthritis In Vivo.

The abnormal fluctuation of temperature in vivo usually reflects the progression of inflammatory diseases. Noninvasive, real-time, and accurate monitoring and imaging of temperature variation in vivo is advantageous for guiding the early diagnosis and treatment of disease, but it remains difficult to achieve. Herein, we developed a temperature-activated near-infrared-II fluorescence (NIR-II FL) and surface-enhanced Raman scattering (SERS) nanoprobe for long-term monitoring of temperature changes in rat arthritis and timely assessment of the status of osteoarthritis. The thermosensitive polymer bearing NIR-II FL dye was grafted onto the surface of nanoporous core-satellite gold nanostructures to form the nanoprobe, wherein the nanoprobe contains NIR-II FL and Raman reference signals that are independent of temperature change. The ratiometric FL1150/FL1550 and S1528/S2226 values of the nanoprobe exhibited a reversible conversion with temperature changes. The nanoprobe accurately distinguishes the temperature variations in the inflamed joint versus the normal joint in vivo by ratiometric FL and SERS imaging, allowing for an accurate diagnosis of inflammation. Meanwhile, it can continuously monitor fluctuations in temperature over an extended period during the onset and treatment of inflammation. The tested temperature change trend could be used as an indicator for early diagnosis of inflammation and real-time evaluation of therapeutic effects.

Effect of Xanthohumol from Humulus lupulus L. Against Gouty Bone Damage in Arthritis of Rats Induced by Mono-sodium Urate.

Xanthohumol (XAN) is an isoprenyl flavonoid from Humulus lupulus L. known for beer brewing, and an osteoprotective agent due to its active improvement in bone loss of osteoporosis. This study was first time to investigate its effects on anti-gouty bone injury in rats of gouty arthritis (GA) induced by monosodium urate (MSU). Results showed that XAN could significantly exert anti-inflammatory activity by alleviating swelling degree of joints, reducing serum level of inflammatory factors, improving inflammatory injury and degrading the Markin's score in lesion joint. Meanwhile, XAN could also fight against gouty bone damage by improving pathological changes of bone tissue and parameters of bone micro-structure. Moreover, XAN could even promote bone formation by effectively enhancing expression of Runx2 and OPG, while inhibit bone resorption with depressing matrix metalloproteinase-9 (MMP-9), MMP-13 and CTSK expression, reducing RANKL secretion, and abating the ratio of RANKL/OPG. Therefore, it was the first time to reveal the mechanism of XAN against gouty bone injury via inhibiting RANKL/OPG/RANK signaling pathway. Above all, this study provided potential strategy for the treatment of GA, and further contributed to research and resource development for hops.

Dexamethasone Palmitate Encapsulated in Palmitic Acid Modified Human Serum Albumin Nanoparticles for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint condition characterized by symmetric, erosive synovitis leading to cartilage erosion and significant disability. Macrophages, pivotal in disease progression, release pro-inflammatory factors upon activation. We developed a nanoparticle delivery system (DXP-PSA NPs), based on palmitic acid modified human serum albumin (PSA), to deliver dexamethasone palmitate (DXP) directly to sites of inflammation, enhancing treatment effectiveness and minimizing possible side effects. The system actively targets scavenger receptor-A on activated macrophages, achieving selective accumulation at inflamed joints. In vitro effect and preliminary targeting abilities were investigated on LPS-activated RAW264.7 cells. The in vivo efficacy and safety were evaluated and compared side to side with commercially available lipid emulsion Limethason® in an advanced adjuvant-induced arthritis rat model. DXP-PSA NPs offer a novel approach to RA treatment and presents promising prospects for clinical translation.

Adipose-derived stem cell exosomes loaded with icariin alleviates rheumatoid arthritis by modulating macrophage polarization in rats

Rheumatoid arthritis (RA) is a chronic autoimmune disease marked by synovitis and cartilage destruction. The active compound, icariin (ICA), derived from the herb Epimedium, exhibits potent anti-inflammatory properties. However, its clinical utility is limited by its water insolubility, poor permeability, and low bioavailability. To address these challenges, we developed a multifunctional drug delivery system—adipose-derived stem cells-exosomes (ADSCs-EXO)-ICA to target active macrophages in synovial tissue and modulate macrophage polarization from M1 to M2. High-performance liquid chromatography analysis confirmed a 92.4 ± 0.008% loading efficiency for ADSCs-EXO-ICA. In vitro studies utilizing cellular immunofluorescence (IF) and flow cytometry demonstrated significant inhibition of M1 macrophage proliferation by ADSCs-EXO-ICA. Enzyme-linked immunosorbent assay, cellular transcriptomics, and real-time quantitative PCR indicated that ADSCs-EXO-ICA promotes an M1-to-M2 phenotypic transition by reducing glycolysis through the inhibition of the ERK/HIF-1α/GLUT1 pathway. In vivo, ADSCs-EXO-ICA effectively accumulated in the joints. Pharmacodynamic assessments revealed that ADSCs-EXO-ICA decreased cytokine levels and mitigated arthritis symptoms in collagen-induced arthritis (CIA) rats. Histological analysis and micro computed tomography confirmed that ADSCs-EXO-ICA markedly ameliorated synovitis and preserved cartilage. Further in vivo studies indicated that ADSCs-EXO-ICA suppresses arthritis by promoting an M1-to-M2 switch and suppressing glycolysis. Western blotting supported the therapeutic efficacy of ADSCs-EXO-ICA in RA, confirming its role in modulating macrophage function through energy metabolism regulation. Thus, this study not only introduces a drug delivery system that significantly enhances the anti-RA efficacy of ADSCs-EXO-ICA but also elucidates its mechanism of action in macrophage function inhibition.Graphical abstract

Liver X receptor inverse agonist SR9243 attenuates rheumatoid arthritis via modulating glycolytic metabolism of macrophages.

Liver X receptors (LXRs) which link lipid metabolism and inflammation, were overexpressed in experimental rheumatoid arthritis (RA) rats as observed in our previous studies, while suppression of LXRα by silybin ameliorates arthritis and abnormal lipid metabolism. However, the role of LXRs in RA remains undefined. In this study, we investigated the inhibition role of LXRs in the polarization and activation of M1 macrophage by using a special LXRs inverse agonist SR9243, which led to ameliorating the progression of adjuvant-induced arthritis (AIA) in rats. Mechanistically, SR9243 disrupted the LPS/IFN-γ-induced Warburg effect in M1 macrophages, while glycolysis inhibitor 2-DG attenuated the inhibition effect of SR9243 on M1 polarization and the cytokines expression of M1macrophages including iNOS, TNF-α, and IL-6 in vitro. Furthermore, SR9243 downregulated key glycolytic enzymes, including LDH-A, HK2, G6PD, GLUT1, and HIF-1α in M1 macrophages, which is mediated by increased phosphorylation of AMPK (Thr172) and reduced downstream phosphorylation of mTOR (Ser2448). Importantly, gene silencing of LXRs compromises the inhibition effect of SR9243 on M1 macrophage polarization and activation. Collectively, for the first time, our findings suggest that the LXR inverse agonist SR9243 mitigates adjuvant-induced rheumatoid arthritis and protects against bone erosion by inhibiting M1 macrophage polarization and activation through modulation of glycolytic metabolism via the AMPK/mTOR/HIF-1α pathway.